x86: Free the symbol buffer and the relocation buffer after use
authorH.J. Lu <hjl.tools@gmail.com>
Tue, 20 Jun 2023 22:10:11 +0000 (15:10 -0700)
committerH.J. Lu <hjl.tools@gmail.com>
Wed, 21 Jun 2023 16:13:34 +0000 (09:13 -0700)
When --no-keep-memory is used, the symbol buffer and the relocation
buffer aren't cached.  When packing relative relocations, we may
allocate a new symbol buffer and a new relocation buffer for each
eligible section in an object file.  If there are many sections,
memory may be exhausted.  In this case, we should free the symbol
buffer and the relocation buffer after use.  If symbol buffer entries
are used to track relative relocations against local symbols for later
use, the symbol buffer should be cached.

PR ld/30566
* elfxx-x86.c (elf_x86_relative_reloc_record_add): Add an
argument to inform caller if the symbol buffer should be kept.
(_bfd_x86_elf_link_relax_section): Call
_bfd_elf_link_info_read_relocs instead of
_bfd_elf_link_read_relocs.  Free the symbol buffer and the
relocation buffer after use.  Cache the symbol buffer if it
is used.

bfd/elfxx-x86.c

index 132fb791ac6dfc8fea481e8180f3e953d6b768e2..8e13a92e7f916d139118c6f2ebaabbf82a885c2d 100644 (file)
@@ -1013,7 +1013,7 @@ elf_x86_relative_reloc_record_add
    struct elf_x86_relative_reloc_data *relative_reloc,
    Elf_Internal_Rela *rel, asection *sec,
    asection *sym_sec, struct elf_link_hash_entry *h,
-   Elf_Internal_Sym *sym, bfd_vma offset)
+   Elf_Internal_Sym *sym, bfd_vma offset, bool *keep_symbuf_p)
 {
   bfd_size_type newidx;
 
@@ -1057,6 +1057,8 @@ elf_x86_relative_reloc_record_add
     {
       relative_reloc->data[newidx].sym = sym;
       relative_reloc->data[newidx].u.sym_sec = sym_sec;
+      /* We must keep the symbol buffer since SYM will be used later.  */
+      *keep_symbuf_p = true;
     }
   relative_reloc->data[newidx].offset = offset;
   relative_reloc->data[newidx].address = 0;
@@ -1086,6 +1088,8 @@ _bfd_x86_elf_link_relax_section (bfd *abfd ATTRIBUTE_UNUSED,
   bfd_vma *local_got_offsets;
   bool is_x86_64;
   bool unaligned_section;
+  bool return_status = false;
+  bool keep_symbuf = false;
 
   if (bfd_link_relocatable (info))
     return true;
@@ -1120,9 +1124,9 @@ _bfd_x86_elf_link_relax_section (bfd *abfd ATTRIBUTE_UNUSED,
 
   /* Load the relocations for this section.  */
   internal_relocs =
-    _bfd_elf_link_read_relocs (abfd, input_section, NULL,
-                              (Elf_Internal_Rela *) NULL,
-                              info->keep_memory);
+    _bfd_elf_link_info_read_relocs (abfd, info, input_section, NULL,
+                                   (Elf_Internal_Rela *) NULL,
+                                   info->keep_memory);
   if (internal_relocs == NULL)
     return false;
 
@@ -1163,11 +1167,13 @@ _bfd_x86_elf_link_relax_section (bfd *abfd ATTRIBUTE_UNUSED,
            {
              isymbuf = (Elf_Internal_Sym *) symtab_hdr->contents;
              if (isymbuf == NULL)
-               isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
-                                               symtab_hdr->sh_info, 0,
-                                               NULL, NULL, NULL);
-             if (isymbuf == NULL)
-               goto error_return;
+               {
+                 isymbuf = bfd_elf_get_elf_syms (abfd, symtab_hdr,
+                                                 symtab_hdr->sh_info,
+                                                 0, NULL, NULL, NULL);
+                 if (isymbuf == NULL)
+                   goto error_return;
+               }
            }
 
          isym = isymbuf + r_symndx;
@@ -1267,7 +1273,8 @@ _bfd_x86_elf_link_relax_section (bfd *abfd ATTRIBUTE_UNUSED,
          if (!elf_x86_relative_reloc_record_add (info,
                                                  &htab->relative_reloc,
                                                  irel, htab->elf.sgot,
-                                                 sec, h, isym, offset))
+                                                 sec, h, isym, offset,
+                                                 &keep_symbuf))
            goto error_return;
 
          continue;
@@ -1336,21 +1343,28 @@ _bfd_x86_elf_link_relax_section (bfd *abfd ATTRIBUTE_UNUSED,
                 ((unaligned_section || unaligned_offset)
                  ? &htab->unaligned_relative_reloc
                  : &htab->relative_reloc),
-                irel, input_section, sec, h, isym, offset))
+                irel, input_section, sec, h, isym, offset,
+                &keep_symbuf))
            goto error_return;
        }
     }
 
   input_section->relative_reloc_packed = 1;
 
-  return true;
+  return_status = true;
 
 error_return:
   if ((unsigned char *) isymbuf != symtab_hdr->contents)
-    free (isymbuf);
+    {
+      /* Cache the symbol buffer if it must be kept.  */
+      if (keep_symbuf)
+       symtab_hdr->contents = (unsigned char *) isymbuf;
+      else
+       free (isymbuf);
+    }
   if (elf_section_data (input_section)->relocs != internal_relocs)
     free (internal_relocs);
-  return false;
+  return return_status;
 }
 
 /* Add an entry to the 64-bit DT_RELR bitmap.  */